1. Field of the Invention
The present invention relates to a device for mounting a screw-rudder on a floating vehicle.
2. Description of the Prior Art
Devices are known for mounting a screw-rudder, comprising a support, substantially vertical slide guide means fastened to the support, and a tubular casing mounted for sliding along the slide guide means for adjusting the depth of immersion of the screw. The tubular casing is adapted to be raised in order to lift the screw out of the water, by power cylinder means connected between the support and the tubular casing to control as required the sliding and lifting of the tubular casing. A steering shaft is mounted for rotation in the tubular casing, and a screw-carrier assembly is rigidly suspended on the said steering shaft.
In known devices of this kind the power cylinder means generally comprises two independent power cylinders, one of which slides the tubular casing for the adjustment of the depth of immersion of the screw, while the other raises the tubular casing in order to lift the screw out of the water for inspection and repair.
In order to simplify the construction it has also been proposed to perform these two functions by means of a single power cylinder, but this cylinder must then have a long stroke, which makes it expensive, increases its dimensions, and introduces potential sources of operating faults.